StickyMicky

i have just found this page

http://www.link-electro.co.nz/pdfs/PossumLink/v5.pdf

values it gives for AFR go againts what i have read on this board
why is this?





[Edited by StickyMicky - 10/30/2003 1:12:48 PM]

AndrewC

Micky,

Why do you say this goes against what you read/been told on here?

Most people use that table as their reference when using the OEM lambda sensor.

Andrew...

StickyMicky

becuase i was told that if my car ran 836 then its running to lean?

seams fine on that table
i tried a test today and wond the boost right down to 0.6bar to see if that had any effect on my lambda voltages

i only used it upto about 3rd gear as its not really yhe time and the place to be flying about and didnt see any voltages any where near the 8.90 im told is correct

StickyMicky

also as was previosly discussed in another thread
the car does hit 855 or simmiler on occasions, which if i rember correctly could indicate figures higher then that due to the scoobymonitor rounding down the values

im a bit hasty towards spending lots of money on parts till im absolutley sure the ones i have are fooked

i still see no on boost knock correction

Jolly Green Monster

iTrader: (4)

I see about 0.72 at 0.5/0.6bar as it is not enough boost to warrent a richer mixture..

I see 0.88 at 0.75 bar and 1bar for the first couple of Wide open throttles and then the lambda slowly under reads until eventually I see 0.72.

This is approximate voltages from the LEDs on my Dawes AFR.

Dunno if that is any help to you..

JGM

AndrewC

Micky,

I'd get it checked with a properly calibrated wideband, it's the only way you'll know what AFR you are actually running.

The OEM sensor is only accurate over a very narrow range and very quickly loses that accuracy when hot.

The best AFR for power is between 13:1 and 13.5:1 although on forced induction cars AFRs less that 12:1 (more like 10.5:1-11.5:1) are used to suppress detonation. I wouldn't be happy running an afr of greater than 13:1 at 1.2bar.

Andrew...

Bob Rawle

The OEM sensor can be used to provide a pretty accurate afr estimate as long as its in good condition, the version used in the Impreza is particularly suited.
You do need to know that the sensor is good though and they do deteriorate quickly, fine for stoich control but not for mapping. As mentioned a wide band is the definitive test. If you want to use a narrow band sensor then use a new oem factory fit item and you will get reasonably accurate readings.
Under those circumstances you should see 0.89/0.9 volts at WOT and 0.85/0.86 at 0.5 bar boost.

cheers

bob